Question: Assume that the following data came from
identically and independently distributed normal
random variables N(u,o^2= 4)
The data
2.929 8.870 3.999 3.285 4.050
6.969 4.454 2.716 4.551 4.019
Find a 98% condence interval for u  Edit

Answer: x bar= 4.5842 (Use excel to find average of 10 numbers).
sigma=sqrt(4)=2
Margin of error,e= {sigma/sqrt(n)} *z_c

z_c=2.33 at 98% confidence.

e=[2/sqrt(10)]*2.33=1.4736

Confidence Interval of mu=(x bar -e, x bar+e)=(4.5842-1.4736, 4.5842 +1.4736)=(3.1106, 6.0578)  Edit